In the automotive repair industry there are well established systems for repairing and aligning vehicles, including trucks and automobiles. The systems include provisions for body straightening by the selective application of tension racking forces to provide rectification, including collision damage. The application of such forces requires precise positioning of the racking mechanisms with the capability to readily relocate and reposition the racking means in relation to a racking frame upon which a subject body is secured. One earlier approach to the positioning of a pulling racking frame involves the provision of a trolley mounted pulling tower, the trolley having a locating bracket at the front end thereof for pinning attachment to an intermediate bracket which, in turn is removably attached to selected ones of a series of pin apertures provided on frame cross members, and on the periphery of the racking frame. The application of racking tensile forces against the vehicle body brings the trolley into compressive, load transfer relation with the racking frame.
The setting up and necessary continued readjustments of this type of prior arrangement is time consuming, labour intensive and very fatiguing for a body man who is occupied full time in using such apparatus. Thus, a heavy trolley having a somewhat massive pulling tower requires to be released from its anchor pin, connecting it with an anchor bracket, and a pair of close fitting shear pins connecting the anchor bracket with the racking frame also released; relocation of trolley and tower to another location relative to the racking frame is then required, with precise realignment of the bracket on the frame at the new location, including aligning the trolley attachment bracket with another pair of racking frame attachment apertures, and reattachment of the trolley to the bracket by the insertion of the nose of the trolley in engaging relation with the bracket, and insertion of the anchor pin in securing relation between the bracket and the trolley. Owing to the massive nature of the apparatus involved such an operation generally of necessity requires two men, in order to effect trolley repositioning and reattachment. Furthermore, repositioning of the bracket on one of the frame cross members can readily involve a great deal of time-consuming manipulation.